Slide 1

Soil Moisture and Soil Temperature Observations and Applications Operated by the

Natural Resources Conservation Service

Garry L. Schaefer, WCM Branch Leader, NWCCDeborah S. Harms, Soil Scientist, NSSC

March 3-5, 2009Oak Ridge, TN

Slide 2

Soil Moisture Monitoring

• SCAN– Soil Climate Analysis Network– Monitors lower elevation areas for climate

parameters and soil moisture monitoring nationwide

• SNOTEL– SNOw pack TELmetry– Monitors high elevation areas for snow

water content, climate parameters, and soil moisture in the Western United States

Slide 3Drought Vulnerable Soil Landscapes

Slide 4

SCAN

• SCAN – Started as a Soil Moisture/Soil Temperature Pilot

Project between the National Water and Climate Center and the National Soil Survey Center in 1991 with 21 stations in 19 states

– If funding becomes available, full implementation of SCAN would have at least 1,000 new stations and integrate 1,000 existing partner-based stations

• Goal will be to have new stations located on Benchmark soil series

– Utilizes meteor burst, line-of-sight, or GOES satellite communication technology to transmit remote station data

Slide 5

SCAN• Currently the network has

151 stations in 39 States• Provides hourly data with

– Precipitation– Air temperature– Relative humidity– Solar radiation– Wind speed and direction– Barometric pressure– Soil moisture and soil

temperature• 2, 4, 8, 20, and 40

inches

Slide 6

Other SCAN Data Parameters

• Snow water content• Snow depth• Net radiation• Redox• Additional soil moisture and soil

temperature measurements• Water level• Surface temperature• Water quality parameters

Slide 7

Slide 8

Soil Moisture/ PrecipitationUAPB Point Remove, AR

Soil Moisture vs. PrecipitationPRELIMINARY DATA SUBJECT TO CHANGE

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Hourly Readings

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Hourly Precipitation 2" Soil Moisture 4" Soil Moisture 8" Soil Moisture 20" Soil Moisture 40" Soil Moisture

Slide 9

SCAN Data• All SCAN stations have full soil

characterizations complete and available on the web

• All historic and real-time SCAN data are available on the web– http:www.wcc.nrcs.usda.gov/scan

• Special Reports– Special “Spreadsheet” compatible reports

can be created

Slide 10

SCAN Future

FY 2009 33 new SCAN stations will be added.– 16 Utah– 4 New Mexico– 10 Alabama– 1 Idaho– 1 Nevada– 1 California

• NRCS is looking at purchase of CONUS Meteor Burst Master Stations for full U.S. Coverage

• NRCS is looking how to fund SCAN• Collaborating on development of spatial soil moisture

modeling

Slide 11

SCAN Cooperators• Current partners include:

– U.S.D.A.- Agricultural Research Service– Mississippi State University and Extension Service– Alabama A&M University– University of Arkansas - Pine Bluff – University of Missouri– Iowa State University– High Plains Regional Climate Center– U.S.D.A.- World Agricultural Outlook Board– U.S.D.A.- Forest Service – U.S.D.A.-Natural Resources Conservation Service– The Nature Conservancy– Vermont Department of Forests, Parks, and Recreation– University of Alaska– SE Regional Climate Center– Others

Slide 12

SNOTEL Network• Large Automated Climate Network

– Began in 1978– Over 754 remote stations– Generally in high elevation areas– Located in the 12 Western States and

Alaska– Utilizes meteor burst communication

technology to transmit data

Slide 13

SNOTEL Network• Large Automated

Climate Network– Began in 1978– 765 remote stations– Generally in high

elevation areas– Located in the 12

Western States including Alaska

– Utilizes meteor burst communication technology to transmit data

Slide 14

SNOTEL Parameters• Typical Sensor Array

– Snow water content– All season precipitation– Air temperature (maximum,

minimum, and average)– Snow depth– Soil moisture and soil temperature at

35% of network

Slide 15

SNOTEL Parameters

• Additional Sensors at Enhanced SNOTEL Stations– Solar radiation– Relative humidity– Wind speed and direction – Other sensors based upon customer

requests

Slide 16

Typical SNOTEL Station

Slide 17

Siting Criteria

• All stations should be located on federal, state, county, or university lands. This will ensure long-term use of the land for monitoring purposes.

• All stations should be located in non-irrigated areas.• First consideration be given to “Benchmark” soils.• Consideration must be given to ensure that all Major Land

Resource Area’s are represented in a given climatic region.• The station must represent an agricultural area. Pasture,

range, timber, and cropped areas must be considered first.• When selecting a suitable location, some consideration of

station security must be included. • The first stations to be installed should be located in areas

that are susceptible to drought.

Slide 18

Soil Moisture/Soil Temperature Measurement

• NRCS uses a capacitance type of sensor.

• Steven Water “Hydro Probe” SDI-12 is currently used

• Installed at specific depths• Full soil description and

characterization analysis are done at each location

• Description and characterization data available to users from the Web

Slide 19

Soil Description

Slide 20

Sensor Placement and Layout

• The deepest sensor is installed first

• 40 inch installed vertically

• Hole is kept to a small size to minimize water transport

Slide 21

Sensor Placement and Layout

• Sensors are placed horizontally at all other depths

• Sensors are dispersed around the small hole to minimize interference

• Compact the soil as each sensor is installed making sure the sensor is inserted completely into undisturbed soil

Slide 22

Sensor Placement and Layout

• Sensor wires are moved to opposite side of hole and form a drip-loop

• Flex-conduit is used to protect sensor wires

Slide 23

Data Uses for SCAN and SNOTEL

• Climate monitoring • Water supply forecasting • Drought assessment and mitigation• Drought triggers • Precision agriculture• Soil survey interruption and mapping • Crop production forecasts• Range production and condition• Disease and Pest prediction/mitigation• Provide data for NWS and other agencies for flood forecasting

and reservoir management• Climate change assessment• Water quality monitoring• Air quality monitoring• Underground utility lines

Slide 24

Summary• SCAN and SNOTEL have a high benefit/cost

ratio• Provide a minimum of daily up to hourly data• Expandable to meet demands• Designed to be a cooperative program• Requires maintenance to ensure data quality• Diverse utility of the data• Data are easily retrievable from the web page

at http://www/wcc.nrcs.usda.gov• Developing better tools to provide user with

spatial soil moisture modeling– Agreement with Oregon State University and

Alabama A&M University to develop a spatial soil moisture model which integrates point soil moisture data with soils data to produce a soil moisture map

Slide 25

Contacts• Garry L. Schaefer, NRCS

Water & Climate Monitoring Branch Leader1201 NE Lloyd Blvd., Suite 802Portland, OR 97232Phone: 503-414-3068 Fax: 503-414-3101Email: garry.schaefer@por.usda.gov

• Deborah S. Harms, NRCSSoil ScientistFederal Building100 Centennial Mall NorthLincoln, NE 68508Phone: 402-437-5324Email: deb.harms@lin.usda.gov